Front Differential Assembly: Adjustment

Using the ST, screw-in the differential side retainer until resistance is felt.
ST 18630AA010 WRENCH COMPL RETAINER
NOTE:
- Screw-in the RH side slightly deeper than the LH side.
- ST WRENCH ASSEMBLY (499787000) can also be used.
  
  Fig 1: Identifying Differential Side Retainer
  Courtesy of SUBARU OF AMERICA, INC.
Remove the oil pump housing.
Remove the liquid gasket from the mating surface completely.
Install the oil pump housing assembly to the converter case, and secure them by tightening the four bolts evenly.
NOTE: Use an old gasket or aluminum washer to prevent damaging the mating surface of the housing.

Tightening torque:

41 N.m (4.2 kgf-m, 30.2 ft-lb)

Fig 2: Installing Oil Pump Housing Assembly
Courtesy of SUBARU OF AMERICA, INC.
Rotate the drive pinion a few times using ST1 and ST2.
ST1 498937110 HOLDER

ST2 499787700 WRENCH

Fig 3: Rotating Drive Pinion
Courtesy of SUBARU OF AMERICA, INC.
Tighten the LH differential side retainer by rotating the shaft until resistance is felt. Then loosen the RH side differential side retainer. Tighten the LH differential side retainer until the pinion shaft no longer turns, and continue to loosen the RH side. This is the "zero" state.

Fig 4: Identifying Differential Side Retainer
Courtesy of SUBARU OF AMERICA, INC.
After reaching the "zero" state, loosen the LH differential side retainer by three notches and secure it with the lock plate. Then after returning the RH differential side retainer, retighten until it stops. Rotate the drive pinion 2 or 3 times. Tighten the RH differential side retainer further by 1-3/4 notches. This sets the preload. Finally, secure the differential side retainer with the lock plate.

Fig 5: Identifying Lock Plate
Courtesy of SUBARU OF AMERICA, INC.

NOTE: Turning the differential side retainer by one notch changes the backlash approx. 0.05 mm (0.0020 in).

Fig 6: Identifying Differential Side Retainer Gap Dimension
Courtesy of SUBARU OF AMERICA, INC.
Install the Subaru genuine axle shafts to the right and left sides of the front differential.
Install the axle shaft to both sides of the front differential section.

Part No. 38415AA000 AXLE SHAFT
Turn the drive pinion several times using ST1, and check to see if the backlash is within the specification using ST2, ST3, ST4 and ST5.
ST1 499787700 WRENCH

ST2 498247001 MAGNET BASE

ST3 498247100 DIAL GAUGE

ST4 499787500 ADAPTER

ST5 498255400 PLATE

Backlash:

0.13 - 0.18 mm (0.0051 - 0.0071 In)

Fig 7: Identifying Adapter, Plate And Dial Gauge
Courtesy of SUBARU OF AMERICA, INC.
Adjust the teeth contact of the front differential and drive shaft. < Ref. to ADJUSTMENT , Drive Pinion Shaft Assembly. >